Alignment guide for cervical spine plate

ABSTRACT

A cervical spine plate attachment system includes a bracket and an alignment guide. The bracket is configured to mount to a cervical spine plate. The alignment guide includes a first connector proximate to a first end of the alignment guide, wherein the first connector is configured to attach to a first pin inserted into a first vertebra. The alignment guide also includes a second connector proximate to a second end of the alignment guide, wherein the second connector is configured to attach to a second pin inserted into a second vertebra. The alignment guide further includes a fastener configured to secure the alignment guide to the bracket such that the alignment guide is secured to the cervical spine plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of U.S. patent applicationSer. No. 15/255,598 filed on Sep. 2, 2016, which is a Continuation ofU.S. patent application Ser. No. 15/200,447 filed on Jul. 1, 2016, whichclaims the priority benefit of U.S. Provisional Patent Application No.62/260,868 filed on Nov. 30, 2015, the entire disclosures of which arehereby incorporated by reference herein.

BACKGROUND

Cervical spine plates are commonly used in anterior cervical spinefusion operations to stabilize the spine while the fusion heals. Thetypical surgical sequence is to perform an anterior cervical discectomy,followed by placement of a structural bone graft or cage with bone graftinto the disk space for the fusion. This is followed by placement of ananterior cervical plate, and screws are used to attach the plate to thevertebral bodies above and below the disk space into which thegraft/cage was placed.

SUMMARY

A cervical spine plate attachment system includes a bracket and analignment guide. The bracket is configured to mount to a cervical spineplate. The alignment guide includes a first connector proximate to afirst end of the alignment guide, wherein the first connector isconfigured to attach to a first pin inserted into a first vertebra. Thealignment guide also includes a second connector proximate to a secondend of the alignment guide, wherein the second connector is configuredto attach to a second pin inserted into a second vertebra. The alignmentguide further includes a fastener configured to secure the alignmentguide to the bracket such that the alignment guide is secured to thecervical spine plate. A cervical spine plate can also be designed toattach directly to an alignment guide without the use of a bracket.

A method for mounting a cervical spine plate includes mounting thecervical spine plate to an alignment guide. The method also includesplacing the alignment guide over distraction pins which are mounted tovertebrae. The method also includes drilling holes into the vertebraesuch that the cervical spine plate can be secured to the vertebrae,wherein the drilling is performed using the secured cervical spine plateas a guide. The method further includes securing the cervical spineplate to the vertebrae with fasteners.

The foregoing is a summary of the disclosure and thus by necessitycontains simplifications, generalizations, and omissions of detail.Consequently, those skilled in the art will appreciate that the summaryis illustrative only and is not intended to be in any way limiting.Other aspects, features, and advantages of the devices and/or processesdescribed herein, as defined by the claims, will become apparent in thedetailed description set forth herein and taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of distraction pins attached to vertebrae inaccordance with an illustrative embodiment.

FIG. 2 is a front view, or an anterior view, of a cervical spine platein accordance with an illustrative embodiment.

FIG. 3A is a front view, or an anterior view, of a bracket that attachesto a cervical spine plate and an alignment guide in accordance with anillustrative embodiment.

FIG. 3B is a front view of a bracket attached to a cervical spine platein accordance with an illustrative embodiment.

FIG. 3C is a side view of a bracket attached to a cervical spine platein accordance with an illustrative embodiment.

FIGS. 4A, 4B, 4C, and 4D are front views, or anterior views, of 4different embodiments of the cervical spine plate alignment guide, inaccordance with illustrative embodiments.

FIGS. 5A, 5B, 5C, and 5D are front views, or anterior views, of thecervical spine plate secured to the cervical spine plate alignment guidevia a bracket, in accordance with illustrative embodiments.

FIGS. 6A and 6B are side views of 2 different embodiments a cervicalspine plate alignment guide being attached to a cervical spine plate viaa bracket, in accordance with illustrative embodiments.

FIG. 7A is a side view of a cervical spine with interbody fusion cagesbetween the vertebral bodies, with a cervical spine plate attached tothe vertebral body on the left and the vertebral body on the right withscrews, in accordance with an illustrative embodiment. Distraction pinsare depicted in the vertebral bodies, and the cervical spine platealignment guide is mounted on the distraction pins. The bracket isattached to the cervical spine plate and is being attached to thecervical spine plate alignment guide with a bolt, in accordance with anillustrative embodiment.

FIG. 7B shows the same configuration as FIG. 7A, with the addition ofclamps that secure the cervical spine plate alignment guide to thedistraction pins, in accordance with an illustrative embodiment.

FIG. 8 is a front view, or anterior view, of a single-level anteriorcervical spine fusion, with a cervical spine plate attached to analignment guide, in accordance with an illustrative embodiment.

FIG. 9 is a front view, or anterior view, of an alternative embodimentof the cervical spine plate alignment guide, in accordance with anillustrative embodiment.

FIGS. 10A through 10E are front or anterior views (FIGS. 10A and 10C)and cross-sectional views (FIGS. 10B, D, and E) of an anterior cervicalspine plate with a groove or channel and screw hole designed to directlymate to an alignment guide without using a bracket, in accordance withillustrative embodiments.

FIG. 11 is a flow diagram depicting a process for mounting a cervicalspine plate using an alignment guide in accordance with an illustrativeembodiment.

DETAILED DESCRIPTION

A cervical spinal fusion can be performed at a single level (i.e.,across a single disc) or multiple levels (i.e., across multiple discs),with a single cervical spine plate spanning the one level or multiplelevels. Ideally the cervical spine plate is placed in the exact midlineof the cervical spine when viewed from the front (i.e., anterior view),but this can be difficult and often the plate ends up being placed tothe left or right of midline during surgery. Spine surgeons often lamentthe difficulty in placing the anterior cervical spine plate in thedesired position. For example, a common method of applying the anteriorcervical spine plate is by provisionally securing the plate to thevertebral body by placing a small pin which may be threaded through theplate into the bone. However, due to the curvature of the anteriorvertebral bodies and other factors, it can be difficult to preciselysecure the plate in the desired position prior to drilling the screwholes and while placing the screws that secure the plate to the bone.The drill can drift slightly cephalad, caudal, left and/or right as thedrilling is done, and the plate ends up then being placed in asuboptimal position.

As a result, a common problem that occurs during such surgeries is thatthe cervical spine plate is positioned slightly to one side or anotherat the upper level and further off to the left or right at the level orlevels below, resulting in the plate being placed slightly obliqueinstead of straight when viewed from the front or on an anteroposterior(AP) X-ray. Even when the plate is applied straight, it can be easy toposition it to the left or right of midline. Another common problem thatoccurs is placement of the plate higher (more cephalad) on the uppermostvertebral body in the fusion construct, which results in the plate beingplaced closer to the uninvolved cephalad disc than is ideal.

Described herein is a cervical spine plate alignment guide that allows asurgeon to easily place the plate in the midline of the cervical spine,straight when viewed from the front and on the anteroposterior (AP)X-ray view, while keeping the plate as low as possible on the uppermostvertebral body in the fusion construct. In order to facilitate ananterior cervical discectomy and fusion, distraction pins can be placedin the vertebral body above and below the fusion. As the disk isremoved, distraction can be placed across the distraction pins, allowingfor better access to the disk space to decompress the neural elements.The cervical spine plate alignment guide is based off of thesedistraction pins. The surgeon places the distraction pins precisely inthe midline of the vertebral bodies above and below the fusion level.Once this is accomplished, the pins can later be used with the alignmentguide to place the plate in the exact desired position. Specifically,the cervical spine plate alignment guide, which is secured to thedistraction pins, functions to rigidly hold the plate in place so thatthe cervical spine plate can be placed in the desired location and sothat it will not move while holes are drilled for the screws. Thissystem and process are described in more detail below with reference tothe figures.

FIG. 1 is a side view of distraction pins attached to vertebrae inaccordance with an illustrative embodiment. Specifically, a distractionpin 125 is attached to a vertebra 100 and a distraction pin 130 isattached to a vertebra 110. The distraction pins span an intervertebraldisc 115 between the vertebra 100 and a vertebra 105, and anintervertebral disc 120 between the vertebra 105 and the vertebra 110.As illustrated in FIG. 1, the distraction pins 125 and 130 each includea threaded end which is threaded into the vertebra to hold it securelyin place. In an illustrative embodiment, the distraction pins 125 and130 are positioned along the midline of the spine when viewed from thefront (i.e., anterior).

FIG. 2 is a front view of a cervical spine plate 200 in accordance withan illustrative embodiment. The cervical spine plate 200 includes aplurality of holes 205 that are configured to receive fasteners suchthat the cervical spine plate 200 can be secured to the vertebral bodiesabove and below a fusion. The fusion over which the cervical spine plate200 spans can be a single level fusion (i.e., a fusion in which a singleintervertebral disc is removed and fused) or a multi-level fusion (i.e.,a fusion in which a plurality of intervertebral discs are removed andfused). The fasteners used to secure the cervical spine plate 200 aretypically screws, although other types of fasteners may be used inalternative embodiments. As illustrated in FIG. 2, a single-level plateincludes four holes, two of which are used to secure the cervical spineplate 200 to a vertebra above, or cephalad to, the fusion and two ofwhich are used to secure the cervical spine plate 200 to a vertebrabelow, or caudal to, the fusion. In alternative embodiments, fewer oradditional holes may be used. For example, in a multilevel fusion, thecervical spine plate may include additional sets of holes such that theplate can be secured to one or more vertebra that occur in between thevertebra directly above the fusion and the vertebra directly below thefusion.

FIG. 3A is a front view of a bracket 300 that attaches to the cervicalspine plate and the cervical spine plate alignment guide in accordancewith an illustrative embodiment. An upper portion 305 of the bracketsits on top of the cervical spine plate, whereas side portions 310 ofthe bracket wrap around the edges of the cervical spine plate, thusattaching the bracket 300 to the plate. The bracket 300 includes ananteriorly protruding component 315 that accommodates the cervical spineplate alignment guide. The cervical spine plate alignment guide issecured to the bracket 300 via a threaded post 320. In an alternativeembodiment, the cervical spine plate alignment guide is secured to thebracket via an alternative locking mechanism.

The bracket 300 is depicted attached to a cervical spine plate 200 inFIG. 3B, in accordance with an illustrative embodiment. The upperportion 305 of the bracket 300 sits on top of (i.e., anterior to) theplate 200, with the side portions 310 of the bracket 300 wrapped aroundthe edges and extending underneath (i.e., posterior to) the cervicalspine plate 200. The bracket 300 attaches to the cervical spine plate200 by an interference fit consisting of the upper portion 305 of thebracket 300 engaging the top of the plate 200 and the side portions 310of the bracket 300 engaging the sides and bottom of the plate 200. Inone embodiment, a back portion of the bracket 300 includes lips, edges,or teeth that are configured to contact a rear side of the cervicalspine plate 200 such that the bracket 300 can be secured to the cervicalspine plate 200. In one embodiment, the lips, edges, or teeth are smallsuch that they extend along only a small portion of the rear side of thecervical spine plate 200 (i.e., just enough to allow the bracket 300 tosecure the cervical spine plate 200). The bracket 300 can besemi-flexible such that the surgeon can bend bracket 300 to open thelips/edges/teeth. The surgeon can then place the bracket 300 on thecervical spine plate 200 and bend the bracket 300 back such that thelips/edges/teeth wrap around to the rear side of the cervical spineplate 200. As discussed in more detail below, the surgeon can thenreverse the process to remove the bracket once the cervical spine plate200 is secured to the patient.

In an alternative embodiment, the bracket 300 can include two halvesthat are slidably mounted to one another via grooves, slots, male/femaleconnection, etc. In such an embodiment, the surgeon does not have tobend the bracket to attach it and remove it from the cervical spineplate 200. Rather, in such an embodiment, the surgeon can slide thebracket open, place the bracket on the cervical spine plate 200, andslide the bracket closed such that the lips/edge/teeth wrap around atleast a portion of the rear side of the cervical spine plate 200. In analternative embodiment, the bracket 300 could be attached to the platevia a screw or post.

FIG. 3C is a cross-sectional view of the bracket 300 attached to thecervical spine plate 200 in accordance with an illustrative embodiment.The bracket includes a protruding component 315 that accommodates thecervical spine plate alignment guide. The cervical spine plate alignmentguide is secured to the bracket via a post 320. Post 320 may or may notbe threaded, depending on the embodiment.

FIG. 4A is a front view of an alignment guide 400 in accordance with anillustrative embodiment. In the embodiment of FIG. 4, the alignmentguide 400 includes an open cylinder or ring 405 that can slide over adistraction pin that is inserted in a vertebra. In alternativeembodiments, different configurations and/or shapes may be used for thealignment guide 400. In an illustrative embodiment, the ring 405 has aninner diameter that is slightly larger than the distraction pin suchthat the ring can be slid over the distraction pin down to the vertebralbody such that the alignment guide 400 can be secured to the patient viaits intimate connection with the distraction pin. In anotherillustrative embodiment, the ring 405 is pivotally mounted via pins 410that run from the outer edges of the ring 405 to bars 415 of thealignment guide 400. In such an embodiment, the ring 405 is able topivot up to 360°. Alternatively, the ring 405 may be attached to thebars 415 via a semi-rigid material (e.g., rubber) that allows the ring405 to pivot in an up/down direction (in accordance with the orientationillustrated in FIG. 4A). The bars 415 are connected by cross members 420and 425 to form a rigid construct having an opening 440 formed by thebars 415 and cross member 425. The opening 440 accommodates adistraction pin that is inserted in a vertebra. Thus the open cylinder405 slides onto a distraction pin in one vertebra and the opening 440accommodates a second distraction pin in a different vertebra such thatthe alignment guide is further secured to the patient. In an alternativeembodiment, opening 440 does not need to accommodate a seconddistraction pin. In the orientation illustrated in FIG. 4A, the ring 405is positioned to be placed over a distraction pin that is inserted abovea fusion and the slot 440 is configured to receive a distraction pinthat is inserted below the fusion. In alternative embodiments, the slot440 can be at the top and the ring 405 may be at the bottom.

FIG. 4B is a front view of an alternative embodiment of an alignmentguide 401 in accordance with an illustrative embodiment. In thisembodiment, the pins 410 connect the ring 405 to short bars 416, whichare connected by cross member 420. Bars 417 then connect to cross member425, which connects to bars 430, thus making an opening 440.

FIG. 4C is a front view of an alternative embodiment of an alignmentguide 450 in accordance with an illustrative embodiment. In thisembodiment, the pins 410 connect the ring 405 to short bars 416, whichare connected by cross member 420. A single bar 455 then connects tocross member 425, which connects to bars 430, thus making an opening440.

FIG. 4D is a front view of an alternative embodiment of an alignmentguide 451 in accordance with an illustrative embodiment. In thisembodiment, a hinge 460 connects the ring 405 to cross member 417. Crossmember 417 then connects to bar 465. Bar 465 connects to cross member425, which connects to bars 430, thus making an opening 440. In analternative embodiment, bar 465 can terminate without connecting to across members, thus eliminating opening 400, with the alignment guideattaching to a single distraction pin. In alternative embodiments, ring405 can be connected by other methods to bars of other configurations tomake an opening 440.

FIG. 5A is a front view of a bracket 300 with protruding component 315between the bars 415 of an alignment guide 400 in accordance with anillustrative embodiment. The bracket 300 includes a protruding component315 and a post 320, and is attached to a cervical spine plate 200. FIG.5B shows the configuration in FIG. 5A with the addition of a fastener525, in accordance with an illustrative embodiment. The fastener 525 canbe a nut or other fastener mechanism, depending on the embodiment.Fastener 525 screws onto threaded post 320 and secures an alignmentguide 400 to a bracket 300, such that plate 200 is attached to bracket300 which is attached to alignment guide 400. FIG. 5C is a front view ofan alternative embodiment of bracket 300 with protruding component 315and threaded post 320 replaced by protruding components 555 and 560 thattogether form a threaded hole that can accept a bolt, in accordance withan illustrative embodiment. The bars of alignment guide 401 run inbetween components 555 and 560. FIG. 5D shows the configuration in FIG.5C with a bolt 570 now screwed into the threaded hole formed bycomponents 555 and 560 in accordance with an illustrative embodiment.This secures an alignment guide 401 to bracket 300, such that plate 200is attached to bracket 300 which is attached to alignment guide 401.

FIG. 6A is a side view of cervical spine plate 200 with an attachedbracket 300 and an alignment guide 400 in accordance with anillustrative embodiment. Ring 405 is attached to the alignment guide 400via pins 410, allowing the ring 405 to pivot. The bracket 300 includes aprotruding component 315 that accommodates the cervical spine platealignment guide. The cervical spine plate alignment guide is secured tothe bracket via a threaded or unthreaded post 320 and a nut or fastener525. Here the nut 525 is depicted in an unsecured fashion, ready to bethreaded onto post 320, thus securing the plate 200 to the alignmentguide 400 via bracket 300. FIG. 6B is an alternative embodiment of analignment guide 401, in accordance with an illustrative embodiment.Threaded post 320 depicted in FIG. 6A is replaced by protrudingcomponents 555 and 560 (560 not pictured in FIG. 6B because it is a sideview, but 560 is pictured in FIG. 5C) that together form threads thatcan accept a bolt 570, and the bars of alignment guide 401 run inbetween components 555 and 560. Here the bolt 570 is depicted in anunsecured fashion, ready to be threaded into the threads formed byprotruding components 555 and 560, thus securing the plate 200 to thealignment guide 401 via bracket 300.

FIG. 7A is a side view of a cervical spine plate 200 positioned onvertebrae in accordance with an illustrative embodiment. In FIG. 7A,representing a 2-level anterior cervical spine fusion, theintervertebral discs 115 and 120 illustrated in FIG. 1 have beensurgically removed and replaced with cages (or bone grafts) 725 and 730.In order to stabilize the spine to facilitate the fusion, the surgeonthen secures the cervical spine plate 200 to the vertebra 100 above(i.e., cephalad to) the fusion sites and the vertebra 110 below (i.e.,caudal to) the fusion sites. As discussed above, the surgeon attachescervical spine plate 200 to an alignment guide 401 and secures thealignment guide 401 to the patient. As illustrated in FIG. 7A, a ring405 of an alignment guide 401 is placed over the distraction pin 125,and a slot 440 of the alignment guide 401 is placed over the distractionpin 130 such that the alignment guide 401 is rigidly secured to thepatient with respect to the cephalad-caudal and medial-lateraldirections. In an alternative embodiment, pins other than distractionpins may be used to secure the alignment guide 401 to vertebrae, andsuch pins may be threaded or unthreaded. As discussed above, thedistraction pins 125 and 130 (or other pins) are placed along a midlineof the cervical spine, thus ensuring the plate will also be placed inthe midline of the cervical spine.

FIG. 7B shows the alignment guide 401 further secured to distractionpins 125 and 130 with locking rings 750 that slide onto the distractionpins and then the locking mechanism 751 is engaged, thus holding theback portion of the cervical plate 200 flush with the anterior vertebralbodies, in accordance with an illustrative embodiment. Locking rings 750secure the plate and alignment guide in the anterior-posterior plane.Once the plate is positioned in the desired cephalad-caudal position,and the plate is flush with the vertebral bodies and locking mechanisms751 engaged, the bolt or fastener 570 is tightened, thus rigidlysecuring the cervical spine plate into position on the cervical spine.FIG. 7A shows bolt or fastener 570 in its untightened configuration,whereas FIG. 7B shows the bolt or fastener 570 in its tightenedposition. Once the alignment guide 401 (which is attached to thecervical spine plate 200 via bracket 300) is secured to the patient, thesurgeon can adjust the plate if necessary by loosening the fastener 570,moving the plate cephalad or caudal, and retightening the fastener 570.As such, the surgeon can be confident that the cervical spine plate 200is in the proper position. This position is in the midline of thecervical spine based on the relationship of the alignment guide to thedistraction pins that are placed in the midline. This position isstraight when viewed from the front based on the relationship of thealignment guide bar(s) to the bracket protuberance(s), which is designedwith minimal tolerance to prevent any angulation in the medial orlateral direction. This position is in the desired cephalad-caudalposition based on the ability to slide the plate only in a cephalad orcaudal manner based on the relationship of the alignment guide to thecorresponding protruberance(s) on the bracket, and then securing theplate to the alignment guide in a reversible manner. Once the cervicalspine plate 200 is properly positioned and secured to the patient viathe bracket 300 and its attachment to alignment guide 401, the surgeonthen drills holes into the vertebrae using the holes 205 (depicted inFIG. 2) of the cervical spine plate 200 as a guide. The cervical spineplate 200 is then fastened to the vertebral bodies 100 and 110 viathreaded screws or fasteners 700 and 705, respectively, that passthrough holes 205. The heads of screws or fasteners 700 do not passthrough holes 205, instead engaging the plate 200 and serving tocompress and hold the plate to the vertebral bodies. In an alternativeembodiment, self-drilling screws or fasteners can be used which mayeliminate the need to drill into the vertebral bodies. In anotheralternative embodiment, pins other than distraction pins may be used tosecure the alignment guide 401 to vertebrae, and such pins may bethreaded or unthreaded. As discussed above, the distraction pins 125 and130 (or other pins) are placed along a midline of the cervical spine.Once the cervical spine plate 200 is fastened to the vertebral bodieswith screws or fasteners 700 and 705, the surgeon can then remove thealignment guide by disengaging locking mechanisms 751, sliding lockingrings 750 off the distraction pins 125 and 130, removing bolt orfastener 570, and then disengaging bracket 300 from plate 200. Thedistraction pins 125 and 130 are then removed, and the surgicalprocedure completed in a manner well known to those practiced in theart.

FIG. 8 is a front view of a single-level cervical spine fusion with analignment guide 401 attached to a cervical spine plate 200 via a bracket300, with the cervical spine plate fastened to vertebral bodies 800 and805, in accordance with an illustrative embodiment. The alignment guide401 includes a ring (405 in FIGS. 7A and 7B) that has been slid over adistraction pin (125 in FIGS. 7A and 7B), and together the ring anddistraction pin are shown as 810 in FIG. 8. The cervical spine plate isfastened to the vertebral bodies by screws or fasteners (700 and 705 inFIG. 7B) that have been placed through holes in the cervical spine plate(205 in FIG. 2), and together the holes in the cervical spine platealong with the screws or fasteners placed through the holes are shown as815 in FIG. 8. FIG. 8 shows that the distraction pins have been placedin the midline of the cervical spine, the alignment guide is secured tothe patient by attaching to or sliding around the distraction pins andthus is also placed in the midline, and by virtue of the cervical spineplate being attached to the alignment guide, the cervical spine plate isplaced straight and in the midline of the cervical spine.

FIG. 9 is a front view of an alignment guide 900 in accordance with anillustrative embodiment. The alignment guide 900 is an alternativeembodiment of an alignment guide 400 as depicted in FIG. 4A and includesan upper ring 915 and a lower ring 920, each of which is configured toslide over distraction (or other) pins that are secured to vertebrae ofa patient. In an illustrative embodiment, each of the upper ring 915 andthe lower ring 920 is able to articulate, as discussed above withreference to the ring 405 of FIG. 4A. The sidewalls of the alignmentguide 900 are formed by upper sidewalls 905 that slidably mate withlower sidewalls 910. The upper sidewalls 905 and lower sidewalls 910 canengage one another via a tongue and groove configuration, a hole andshaft configuration, etc. As a result, the alignment guide 900 isadjustable and can be adjusted to fit different patient anatomies anddistraction pins that are different distances apart. A fastener 925 isused to secure the alignment guide 900 to a cervical spine plate asdiscussed herein.

In an alternative embodiment, a cervical spine plate can be designedwith grooves on its front (i.e., anterior) surface in which an alignmentguide sits and is confined such that it can slide in only cephalad andcaudal directions. Such a cervical spine plate can be designed toinclude a threaded hole that can accommodate a bolt or fastener thatdirectly secures the alignment guide to the plate once the plate is inthe desired position on the cervical spine, thus eliminating the needfor a bracket. FIG. 10A is a front view of such a plate, in accordancewith an illustrative embodiment. The cervical spine plate 1000 includesa plurality of holes 1005 that are configured to receive fasteners(usually screws) such that the cervical spine plate 1000 can be securedto the vertebral bodies above and below a fusion, analogous to thecervical spine plate and holes as depicted in FIG. 2. Cervical spineplate 1000 has a central groove 1020 in the top or anterior part of theplate, with side walls 1010 that accommodate a cervical spine alignmentguide and contain it in such a fashion that the cervical spine plate canslide only cephalad or caudal with respect to the alignment guide. Theside walls 415 of cervical alignment guide 400 sit within the groove1020 (shown in FIG. 10C), contained by side walls 1010 of the cervicalspine plate. A central hole 1030 is used to accommodate a fastener tosecure the plate to the alignment guide once properly positioned.

FIG. 10B is a cross-sectional view of cervical spine plate 1000, withthe cross-section occurring through plane 1040 as shown in FIG. 10A, inaccordance with an illustrative embodiment. Groove 1020 is shown alongwith central hole 1030. FIG. 10C is a front view of cervical spine plate1000 with alignment guide 400 secured in position in the groove in thecervical spine plate by fastener or bolt 1025, in accordance with anillustrative embodiment. FIG. 10D is a cross sectional view of cervicalspine plate 1000 with alignment guide 400 sitting in groove 1020, inaccordance with an illustrative embodiment. The cross-section is madethrough plane 1040 as shown in FIG. 10C. In this cross-sectional figure,the side walls 415 of alignment guide 400 are seen to sit within groove1020, such that alignment guide 400 is contained within the groove andcan slide only in cephalad and caudal directions as discussed herein.Fastener or bolt 1025 is ready to be advanced into hole 1030 to securethe alignment guide 400 to the plate 1000 once the plate is positionedin the desired location.

FIG. 10E is a cross sectional view of a cervical spine plate 1050 inaccordance with an illustrative embodiment. The cross-section is madethrough plane 1040 as shown in FIG. 10C. Cervical spine plate 1050 is analternative embodiment of a cervical spine plate that directly attachesto an alignment guide, with a channel 1055 created by protuberances 1060that project from the front or anterior portion of the plate. Thus thechannel 1055 is created with protuberances from the plate rather than agroove in the plate such as groove 1020 in FIG. 10A. The channel 1055serves the same function as groove 1020, that is, containing thecervical spine plate alignment guide side walls such that the alignmentguide can slide only in cephalad or caudal directions. In an alternativeembodiment, a cervical spine plate can be made with a combination of agroove and protuberances to contain the side walls of the cervical spinealignment guide. In another alternative embodiment, the groove orchannel can be made variably wider than the width of the alignmentguide, to allow adjustment in medial and lateral directions in additionto cephalad and caudal directions.

FIG. 11 is a flow diagram depicting a process for mounting a cervicalspine plate using an alignment guide in accordance with an illustrativeembodiment. In alternative embodiments, fewer, additional, and/ordifferent operations may be performed. Additionally, the use of a flowdiagram is not meant to be limiting with respect to the order ofoperations performed. After preliminary surgical procedures areperformed, a surgeon inserts distraction pins into vertebrae in anoperation 1100. In an illustrative embodiment, the distraction pins areinserted into the midline of the patient's spine. As known to those ofskill in the art, the surgeon can use the distraction pins to helpremove one or more intervertebral discs and replace them with bonegrafts or cages. In an embodiment in which distraction pins are notrequired, the surgeon can use other types of pins.

In an operation 1105, the surgeon attaches a cervical spine plate to analignment guide. In an illustrative embodiment, the cervical spine plateis attached to the alignment guide as discussed above with reference toFIGS. 5B and 5D, and FIG. 10C. In an operation 1110, the surgeon placesthe alignment guide over the distraction pins. Specifically, the surgeonslides the rings/slots of the alignment guide over the distraction pinssuch that the alignment guide, and therefore the cervical spine plate,are rigidly secured to the patient. In an operation 1115, the surgeonadjusts the cervical spine plate if necessary. Such adjustment can beperformed by loosening the fastener that secures the alignment guide tothe cervical spine plate, adjusting the cervical spine plate to thedesired orientation, and then re-tightening the fastener to secure thecervical spine plate in the desired orientation.

In an operation 1120, the surgeon drills holes for securing the cervicalspine plate to the vertebra. In an illustrative embodiment, the holes inthe cervical spine plate act as a guide for the drilling. In anoperation 1125, the surgeon secures the cervical spine plate to thepatient by inserting fasteners through the cervical spine plate and intothe drilled holes. In an illustrative embodiment, the fasteners arescrews. In an operation 1130, the surgeon removes the alignment guide,and removes the bracket if a bracket was used, from the cervical spineplate. Specifically, the surgeon can loosen the fastener on thealignment guide, remove the alignment guide by sliding it back off ofthe distraction pins, and manipulate the bracket such that it can beremoved from the cervical spine plate. In an operation 1135, the surgeonremoves the distraction pins from the patient. The surgeon can thencomplete the surgical procedure as known to those of skill in the art.

The alignment guides described herein can be made in a variety oflengths to accommodate single-level and multi-level fusions, andsuitable to various patient anatomies. The alignment guide and othercomponents can be made from stainless steel, titanium, titanium-alloy,cobalt-chrome, or any suitable material that is determined to withstandthe biomechanical stresses under which they will be placed.

The foregoing description of illustrative embodiments has been presentedfor purposes of illustration and of description. It is not intended tobe exhaustive or limiting with respect to the precise form disclosed,and modifications and variations are possible in light of the aboveteachings or may be acquired from practice of the disclosed embodiments.It is intended that the scope of the invention be defined by the claimsappended hereto and their equivalents.

What is claimed is:
 1. A cervical spine plate attachment systemcomprising: a cervical spine plate; and an alignment guide, wherein thealignment guide comprises: a first connector proximate to a first end ofthe alignment guide, wherein the first connector is configured to attachto a first pin inserted into a first vertebra; a second connectorproximate to a second end of the alignment guide, wherein the secondconnector is configured to attach to a second pin inserted into a secondvertebra; at least one sidewall, wherein the sidewall includes an uppersidewall and a lower sidewall, and wherein the upper sidewall slidablymates with the lower sidewall such that a length of the alignment guideis adjustable; and a fastener configured to secure the alignment guideto the cervical spine plate.
 2. The cervical spine plate attachmentsystem of claim 1, wherein the upper sidewall and the lower sidewallengage one another via a tongue and groove configuration.
 3. Thecervical spine plate attachment system of claim 1, wherein the cervicalspine plate includes a central groove with sidewalls.
 4. The cervicalspine plate attachment system of claim 3, wherein the sidewalls of thecentral groove are configured to receive the at least one sidewall ofthe alignment guide.
 5. The cervical spine plate attachment system ofclaim 3, further comprising a threaded opening within the groove,wherein the threaded opening is configured to receive the fastener. 6.The cervical spine plate attachment system of claim 1, furthercomprising protuberances that form a channel on a surface of thecervical spine plate.
 7. The cervical spine plate attachment system ofclaim 6, wherein the channel formed by the protuberances is configuredto receive the at least one sidewall of the alignment guide.
 8. Thecervical spine plate attachment system of claim 6, further comprising athreaded opening within the channel formed by the protuberances, whereinthe threaded opening is configured to receive the fastener.
 9. Thecervical spine plate attachment system of claim 1, wherein the firstconnector comprises a first ring that is pivotally mounted to thealignment guide.
 10. The cervical spine plate attachment system of claim9, wherein the second connector comprises a second ring that ispivotally mounted to the alignment guide.
 11. The cervical spine plateattachment system of claim 9, wherein the second connector comprises aslot formed in part by parallel bars.
 12. The cervical spine plateattachment system of claim 11, wherein the at least one sidewall of thealignment guide comprises a pair of sidewalls, and wherein the parallelbars that form the slot are extensions of the pair of sidewalls of thealignment guide.
 13. The cervical spine plate attachment system of claim1, further comprising first and second locking rings configured to slideover the first pin and the second pin to secure the alignment guide tothe first pin and the second pin.
 14. A method for mounting a cervicalspine plate, the method comprising: mounting a cervical spine plate toan alignment guide, wherein the alignment guide includes a sidewallhaving an upper sidewall and a lower sidewall, and wherein the uppersidewall slidably mates with the lower sidewall such that a length ofthe alignment guide is adjustable; adjusting the length of the alignmentguide by manipulating the upper sidewall and the lower sidewall suchthat the length of the alignment guide matches a distance betweendistraction pins which are mounted to vertebrae; placing the alignmentguide over the distraction pins which are mounted to the vertebrae;using the secured cervical spine plate as a guide, drilling holes intothe vertebrae such that the cervical spine plate can be secured to thevertebrae; and securing the cervical spine plate to the vertebrae withfasteners.
 15. The method of claim 14, further comprising removing thealignment guide from the cervical spine plate.
 16. The method of claim14, further comprising mounting the distraction pins at a midline of thevertebrae.
 17. The method of claim 14, wherein placing the alignmentguide over the distraction pins comprises sliding a first articulatingring of the alignment guide over a first distraction pin.
 18. The methodof claim 17, wherein placing the alignment guide over the distractionpins comprises sliding a second articulating ring of the alignment guideover a second distraction pin.
 19. The method of claim 14, furthercomprising securing the alignment guide to the distraction pins byplacing locking rings over the distraction pins once the alignment guideis in place.
 20. The method of claim 14, wherein mounting the cervicalspine plate to the alignment guide includes inserting the alignmentguide into a groove formed on the cervical spine plate.